cars a/c shutting off?

well i just bought this 91 suzuki sidekick for a good deal but once you turn the a/c on the car cools after a couple minutes of driving with the a/c on the air becomes hot again and you have to shut it off for about 5 minutes until it starts to cool again does anyon know what it could be ?

I have an older subaru that had a "revolution sensor" on the AC compressor wheel. The sensor had gone bad so the computer thought the compressor was spinning too slowly and would disengage the clutch. Replacing the revolution sensor fixed it. Perhaps there is something similar going on here.

If the system is running low on refrigerant, there are a number of pressure switches in the system that can trigger a disengage of the compressor. To avoid running the pump when pressure is too high, or when there is not sufficient refrigerant to lubricate the pump. (There's oil mixed in with the freon) Look for excessive ice formation around fittings or valves, as this may indicate a leak.